SQL Server Always On Availability Groups is Microsoft’s latest technology for addressing the High Availability and Disaster Recovery needs of organizations that use SQL Server. One big advantage of AlwaysOn is the ability to address both HA and DR in one implementation. We experienced the following key benefits of AlwaysOn:
We can group related databases as part of a single Availability Group and have them failover together in case this is needed. This is especially useful for applications that depend on more than one database, such as Microsoft Office SharePoint, Microsoft Lync, and Sage.
When compared to SQL Server Failover Cluster Instances, we find that storage as a single point of failure has been eliminated since each instance which constitutes a replica is assigned its own storage.
With AlwaysOn, it is possible to configure HA and DR at once. This is achieved by creating a Multi-site Windows Failover Clusters as the foundations of your AlwaysOn configuration. Performing a Role Switch when using AlwaysOn is significantly simpler than doing it when using Transaction Log Shipping.